diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/xen/enlighten_pv.c | 135 |
1 files changed, 94 insertions, 41 deletions
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index 5004feb16783..f82857e48815 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -30,7 +30,8 @@ #include <linux/pci.h> #include <linux/gfp.h> #include <linux/edd.h> -#include <linux/objtool.h> +#include <linux/reboot.h> +#include <linux/virtio_anchor.h> #include <xen/xen.h> #include <xen/events.h> @@ -107,8 +108,22 @@ struct tls_descs { */ static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc); +static __read_mostly bool xen_msr_safe = IS_ENABLED(CONFIG_XEN_PV_MSR_SAFE); + +static int __init parse_xen_msr_safe(char *str) +{ + if (str) + return strtobool(str, &xen_msr_safe); + return -EINVAL; +} +early_param("xen_msr_safe", parse_xen_msr_safe); + static void __init xen_pv_init_platform(void) { + /* PV guests can't operate virtio devices without grants. */ + if (IS_ENABLED(CONFIG_XEN_VIRTIO)) + virtio_set_mem_acc_cb(xen_virtio_restricted_mem_acc); + populate_extra_pte(fix_to_virt(FIX_PARAVIRT_BOOTMAP)); set_fixmap(FIX_PARAVIRT_BOOTMAP, xen_start_info->shared_info); @@ -165,7 +180,6 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx, *bx &= maskebx; } -STACK_FRAME_NON_STANDARD(xen_cpuid); /* XEN_EMULATE_PREFIX */ static bool __init xen_check_mwait(void) { @@ -624,6 +638,9 @@ static struct trap_array_entry trap_array[] = { TRAP_ENTRY(exc_coprocessor_error, false ), TRAP_ENTRY(exc_alignment_check, false ), TRAP_ENTRY(exc_simd_coprocessor_error, false ), +#ifdef CONFIG_X86_KERNEL_IBT + TRAP_ENTRY(exc_control_protection, false ), +#endif }; static bool __ref get_trap_addr(void **addr, unsigned int ist) @@ -758,6 +775,7 @@ static void xen_load_idt(const struct desc_ptr *desc) { static DEFINE_SPINLOCK(lock); static struct trap_info traps[257]; + static const struct trap_info zero = { }; unsigned out; trace_xen_cpu_load_idt(desc); @@ -767,7 +785,7 @@ static void xen_load_idt(const struct desc_ptr *desc) memcpy(this_cpu_ptr(&idt_desc), desc, sizeof(idt_desc)); out = xen_convert_trap_info(desc, traps, false); - memset(&traps[out], 0, sizeof(traps[0])); + traps[out] = zero; xen_mc_flush(); if (HYPERVISOR_set_trap_table(traps)) @@ -909,14 +927,18 @@ static void xen_write_cr4(unsigned long cr4) native_write_cr4(cr4); } -static u64 xen_read_msr_safe(unsigned int msr, int *err) +static u64 xen_do_read_msr(unsigned int msr, int *err) { - u64 val; + u64 val = 0; /* Avoid uninitialized value for safe variant. */ if (pmu_msr_read(msr, &val, err)) return val; - val = native_read_msr_safe(msr, err); + if (err) + val = native_read_msr_safe(msr, err); + else + val = native_read_msr(msr); + switch (msr) { case MSR_IA32_APICBASE: val &= ~X2APIC_ENABLE; @@ -925,23 +947,39 @@ static u64 xen_read_msr_safe(unsigned int msr, int *err) return val; } -static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high) +static void set_seg(unsigned int which, unsigned int low, unsigned int high, + int *err) { - int ret; - unsigned int which; - u64 base; + u64 base = ((u64)high << 32) | low; - ret = 0; + if (HYPERVISOR_set_segment_base(which, base) == 0) + return; + if (err) + *err = -EIO; + else + WARN(1, "Xen set_segment_base(%u, %llx) failed\n", which, base); +} + +/* + * Support write_msr_safe() and write_msr() semantics. + * With err == NULL write_msr() semantics are selected. + * Supplying an err pointer requires err to be pre-initialized with 0. + */ +static void xen_do_write_msr(unsigned int msr, unsigned int low, + unsigned int high, int *err) +{ switch (msr) { - case MSR_FS_BASE: which = SEGBASE_FS; goto set; - case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set; - case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set; - - set: - base = ((u64)high << 32) | low; - if (HYPERVISOR_set_segment_base(which, base) != 0) - ret = -EIO; + case MSR_FS_BASE: + set_seg(SEGBASE_FS, low, high, err); + break; + + case MSR_KERNEL_GS_BASE: + set_seg(SEGBASE_GS_USER, low, high, err); + break; + + case MSR_GS_BASE: + set_seg(SEGBASE_GS_KERNEL, low, high, err); break; case MSR_STAR: @@ -957,31 +995,42 @@ static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high) break; default: - if (!pmu_msr_write(msr, low, high, &ret)) - ret = native_write_msr_safe(msr, low, high); + if (!pmu_msr_write(msr, low, high, err)) { + if (err) + *err = native_write_msr_safe(msr, low, high); + else + native_write_msr(msr, low, high); + } } +} + +static u64 xen_read_msr_safe(unsigned int msr, int *err) +{ + return xen_do_read_msr(msr, err); +} + +static int xen_write_msr_safe(unsigned int msr, unsigned int low, + unsigned int high) +{ + int err = 0; - return ret; + xen_do_write_msr(msr, low, high, &err); + + return err; } static u64 xen_read_msr(unsigned int msr) { - /* - * This will silently swallow a #GP from RDMSR. It may be worth - * changing that. - */ int err; - return xen_read_msr_safe(msr, &err); + return xen_do_read_msr(msr, xen_msr_safe ? &err : NULL); } static void xen_write_msr(unsigned int msr, unsigned low, unsigned high) { - /* - * This will silently swallow a #GP from WRMSR. It may be worth - * changing that. - */ - xen_write_msr_safe(msr, low, high); + int err; + + xen_do_write_msr(msr, low, high, xen_msr_safe ? &err : NULL); } /* This is called once we have the cpu_possible_mask */ @@ -1068,8 +1117,7 @@ static void xen_machine_halt(void) static void xen_machine_power_off(void) { - if (pm_power_off) - pm_power_off(); + do_kernel_power_off(); xen_reboot(SHUTDOWN_poweroff); } @@ -1177,16 +1225,26 @@ static void __init xen_domu_set_legacy_features(void) x86_platform.legacy.rtc = 0; } +extern void early_xen_iret_patch(void); + /* First C function to be called on Xen boot */ -asmlinkage __visible void __init xen_start_kernel(void) +asmlinkage __visible void __init xen_start_kernel(struct start_info *si) { struct physdev_set_iopl set_iopl; unsigned long initrd_start = 0; int rc; - if (!xen_start_info) + if (!si) return; + clear_bss(); + + xen_start_info = si; + + __text_gen_insn(&early_xen_iret_patch, + JMP32_INSN_OPCODE, &early_xen_iret_patch, &xen_iret, + JMP32_INSN_SIZE); + xen_domain_type = XEN_PV_DOMAIN; xen_start_flags = xen_start_info->flags; @@ -1195,7 +1253,6 @@ asmlinkage __visible void __init xen_start_kernel(void) /* Install Xen paravirt ops */ pv_info = xen_info; pv_ops.cpu = xen_cpu_ops.cpu; - paravirt_iret = xen_iret; xen_init_irq_ops(); /* @@ -1341,10 +1398,6 @@ asmlinkage __visible void __init xen_start_kernel(void) xen_acpi_sleep_register(); - /* Avoid searching for BIOS MP tables */ - x86_init.mpparse.find_smp_config = x86_init_noop; - x86_init.mpparse.get_smp_config = x86_init_uint_noop; - xen_boot_params_init_edd(); #ifdef CONFIG_ACPI |